Give every view a TSIG key that selects it

Each view's match-clients starts with "key jarl-view-NAME" (after
"!key" for the views listed after it), so a query signed with a view's
key lands in that view from any address. The secrets are derived from a
random seed in Jarl's database. The delegation check signs its queries
to this server's own addresses with the key of the zone's view: before,
they got whichever view matched the server's address, usually internal.
jarl view key / GET /views/{id}/key show a key for dig -k (tsig:write,
audited). jarl-view- key names are reserved; the importer drops view
keys from a configuration Jarl wrote.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

internal/engine/blocklists.go

@@ -78,7 +78,7 @@ func (e *Engine) RefreshDue(ctx context.Context) {
 		e.log.Warn("blocklists: loading their status failed", "err", err)
 		return
 	}
-	out := render.Render(st, e.cfg.Paths, e.cfg.Extras)
+	out := render.Render(st, e.cfg.Paths, e.extras(ctx))
 	if err := e.ensureBlocklistFiles(out.Blocklists); err != nil {
 		e.log.Warn("blocklists: creating empty zone files failed", "err", err)
 	}